Special Information:
If aqueous solutions of thymidine are stored frozen (-20°C), care should be taken to protect the material from U.V. light during the thawing process to prevent possible dimerization.

When [methyl-3H]thymidine is incorporated into cellular DNA and undergoes radiolytic decomposition, [3H]5-hydroxymethyl-2''-deoxyuridine (HMdU) is formed.* The formation of HMdU through transmutation of [methyl-3H]thymidine occurs at the rate of B-decay, which is 0.017% per day. The transmutation product is not volatile.